Glossary:

Acidic Water: Acidic water has a pH of less than 7, (which is neutral) and alkaline water has a pH of more than 7. Acid water has more free hydrogen ions (H+) than hydroxyl ions (OH-). Most wetlands have acidic water because of the decaying organic material of wetland vegetation.

Activated Carbon: Material used in water conditioning. It is very porous and acts as an absorbent for organic matter and some dissolved gases. Homeowners with carbon filters should pay attention to service and maintenance instructions.

Aeration: Process of bringing air into contact with water to remove or reduce unwanted dissolved gases and/or to oxidize dissolved compounds. For example, aeration devices can be effective for removing radon and odor from water.

Absorption: Problematic water(odor etc.) that is treated by penetrating into a substance that is layered in a filter (most often carbon) that absorbs odor. Absorption filters do not require backwashing and have to be serviced periodically by the homeowner to refresh the media.

Alkalinity: The capacity of water for neutralizing an acid solution.

Anaerobic: A condition of oxygen deficiency found in some saturated soils. Changes of oxygen levels in soils and rock sediments can have important effects on ground water chemistry.

Aquifer: (1.)The three dimensional sub-surface geometry of a geologic rock formation (or, group of rock formations or part of a formation) that contains ground water in the spaces between sediment grains, in voids, or in fractures.

(2.) A geological formation or structure that has the capability to store and/or transmit water to wells and springs. Use of the term aquifer is usually restricted to those water-bearing formations capable of yielding water in sufficient quantity to constitute a usable supply source.

Artesian Aquifers: Artesian aquifers (confined aquifers) occur where overlying impermeable rock layers "trap" ground water under pressure. Depending on geology and topography, a single aquifer may be artesian (confined) in one place and unconfined in another.

Artesian Water: Ground water that is under pressure when tapped by a well and is able to rise above the level at which it is first encountered. It may or may not flow out at ground level. The pressure in such an aquifer commonly is called artesian pressure, and the formation containing artesian water is an artesian aquifer or confined aquifer.

Artesian Wells: Wells (bore holes) that penetrate artesian aquifers. Water will rise up the well casing to the pressure level of the aquifer. Artesian flow describes the natural flow to the surface of water from confined aquifers. In some parts of the US any well drilled into bedrock is (incorrectly) called an artesian well.

Bedrock: The solid, but often fractured and fissured, rock formations that occur beneath soils, unconsolidated sediment deposits or weathered materials. Exposed bare rock is bedrock at the surface. Sediments or weathered material overlying bedrock is sometimes called regolith or overburden.

Bicarbonate: Alkalinity in water is usually composed of bicarbonate and is reported as mg/L CaCO3.

Brackish Water: Water that is salty, but less salty than seawater. Seawater has 35,000 mg/L of salts, and is described a saline.

Brine: Salty water with more than 10,000 mg/L of salts (principally sodium chloride).

Calcite: Calcium carbonate (CaCO3) is the principal mineral in limestone.

Carbonates: Rocks such as limestone and dolomite that are comprised principally of carbonate minerals.

Domestic Water Use: Water used for household purposes, such as drinking, food preparation, bathing, washing clothes, dishes, flushing toilets, and watering lawns and gardens. About 85% of domestic water in the U.S. is delivered to homes by a public supply facility, such as a county water department. About 15% of the USA's population supplies their own water, mainly from wells.

Freshwater: Water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses. Sea water contains about 35,000 mg/l of dissolved solids, mostly sodium and chloride.

Grains per Gallon: A unit of measurement still used in some North American water analyses. One grain per US gallon is equivalent to 17.12 milligrams per liter.

Hardness: A water quality index that describes the concentration of alkaline salts in water, mainly calcium and magnesium. If water is "hard" then more soap, detergent or shampoo is necessary to make bubbles for effective washing/ cleaning. Hardness is measured in milligrams per liter (mg/l) but may also be reported in the archaic form of grains per gallon. [One grain of hardness equals 17.1mgl] Typical water hardness classifications are:

Soft water	less than 17mg/l
Slightly hard	17 - 60 mg/l
Moderately hard	60-120 mg/l
Hard	120-180 mg/l
Very hard	180 + mg/l

Limestone: A sedimentary rock consisting principally of calcium carbonate. Limestones may be formed by deposits of shell/corals and/or from chemical precipitation in shallow seas.

Milligram (mg): One thousandth of a gram.

Milligrams per liter (mg/l): Unit of the concentration of a constituent in water or wastewater. It represents 0.001 gram of a constituent in 1.000 milliliter (mL) of water. It is approximately equal to one part per million (PPM).

Monitoring Well: A well constructed or used for the purposes of water level or water quality data collection. Monitoring wells are often installed to provide an early warning of contamination occurring down gradient from a landfill or industrial facility.

Municipal Water System: A water system that has at least fifteen service connections or which regularly serves 25 individuals for 60 days; also called a public water system.

Osmosis: The movement of water molecules through a thin membrane. Reverse osmosis is a water treatment process used to remove or reduce salts from saline water.

Pesticide: Any chemical used for control of plant or animal pests. Pesticides include insecticides, herbicides, fungicides, nematocides, and rodenticides.

pH: A measure of the relative acidity or alkalinity of water. Water with a pH of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions. The range is 1 - 14.

Potable Water: Water of a quality suitable for drinking.

Pressure Tank: A tank installed as part of a water system to minimize the on-off cycles of the well pump. Pressure tanks typically store a few gallons of water and obtain their pressure from the well pump.

Raw Water: Untreated water of any kind.

Reverse Osmosis: The process of removing salts from water using a membrane. Pressure from a pump is used to reverse the normal osmotic process resulting in the solvent moving from a solution of higher concentration to one of lower concentration. The water passes through a fine membrane that the salts are unable to pass through, the remaining salt waste (brine) is removed.

TDS (Total Dissolved Solids): The amount of dissolved material in water usually measured in milligrams per liter (mg/L).

Turbidity: The amount of solid particles that are suspended in water and that cause light rays shining through the water to scatter. Thus, turbidity makes the water cloudy or even opaque in extreme cases. Turbidity is measured in nephelometric turbidity units (NTU).

Waste Water: Water that has been used in homes, industries, and businesses that is not suitable for reuse as a drinking source unless it is treated.

Water Table: The water table is the upper surface of the saturated zone of an unconfined aquifer. The water table may be located at or near the land surface, or at some depth below the land surface. The depth of the water table may fluctuate seasonally throughout the year. Wetlands, springs, and seepages may occur where the water table intersects the land surface.

Water Well: The amount of solid particles that are suspended in water and that cause light rays shining through the water to scatter. Thus, turbidity makes the water cloudy or even opaque in extreme cases. Turbidity is measured in nephelometric turbidity units (NTU).

Well: A hole in the ground made to gain access to an aquifer to obtain water for economic use. Wells may be dug (mostly old wells less than 50 feet deep) or drilled. Drilled water wells in solid rock are typically up to 300 feet deep. Wells in alluvial and glacial sediments are typically about 100 feet deep.